Vitamin D and tuberculosis: review and association in three rural provinces of Afghanistan

• Published in: The international journal of tuberculosis and lung disease Vol. 20; no. 3; pp. 383 - 388
• Main Authors: Sarin, P., Duffy, J., Mughal, Z., Hedayat, E., Manaseki-Holland, S.
• Format: Journal Article
• Language: English
• Published: France International Union Against Tuberculosis and Lung Disease 01-03-2016
• Subjects: 25-Hydroxyvitamin D; Afghanistan - epidemiology; Body Mass Index; Databases, Factual; Enzyme-Linked Immunosorbent Assay; Humans; Meta-Analysis as Topic; Mycobacterium; Mycobacterium Tuberculosis; Rural Afghanistan; Rural Population; Socioeconomic Factors; Tuberculosis - blood; Tuberculosis - epidemiology; Vitamin D - blood; Vitamin D Deficiency; Vitamin D Deficiency - blood; Vitamin D Deficiency - epidemiology
• ISSN: 1027-3719; 1815-7920
• DOI: 10.5588/ijtld.15.0303

OBJECTIVES: 1) To update the 2006 systematic review and meta-analysis by Nnoaham & Clarke exploring the association between serum vitamin D and risk of active tuberculosis (TB) following discrepant evidence; and 2) to identify whether TB and vitamin D are associated in rural Afghanistan.METHODS: Systematic review and meta-analysis of studies published between January 1980 and June 2014 using Nnoaham & Clarke's methodology. For this case-control study, 90 age- and sex-matched pairs were recruited from rural provinces, and blood 25-hydroxyvitamin D concentrations were measured using enzyme-linked immunosorbent assay.RESULTS: Sixteen studies were eligible for review. Eleven showed differences between vitamin D levels in TB patients and controls, two showed partial differences and three showed none. Studies on African and European populations show lower vitamin D levels in TB patients, but results from Asia vary. No significant differences were found in vitamin D levels in our rural Afghan population. Controls had a higher body mass index (BMI) (mean control BMI 21.50 kg/m2, mean case BMI 18.86 kg/m2, P < 0.001), and were more likely to have been employed (40% of controls, 15.6% of cases, P = 0.002).CONCLUSION: Genetic differences may account for the differences among study results in the systematic review. Vitamin D levels are not associated with TB among Afghans living in these rural provinces.